E4 displayed, unit does not keep correct time or program settings

Safety: Unplug the unit before removing the control panel.

• 1. Power cycle: Disconnect power for at least 5 minutes to allow capacitors to discharge. Plug back in and reprogram the time and hardness settings according to the RainSoft manual.
• 2. Check power quality: Verify the outlet is properly grounded and not shared with high-load devices (pumps, compressors). Use a surge protector rated for appliances.
• 3. Inspect board: Remove the control cover and visually inspect the PCB for burn marks, swollen capacitors, or corrosion from moisture.
• 4. Confirm stable voltage: Use a multimeter to verify 120V (or local standard) at the outlet and at the control input. Large fluctuations can cause memory errors.
• 5. Replace control board: If E4 persists after reset and power checks, the control board is likely defective. Order the exact RainSoft control module for your model and transfer wiring one connector at a time to avoid miswiring.

Note: Board replacement is straightforward but requires careful handling of static-sensitive components. If unsure, have a RainSoft dealer perform the swap.